LOS ANGELES (AP)  If Nicolas Cage lights a cigarette in a movie, Hollywood's ratings board should respond as if he used a profanity, according to authors of a new study that criticizes glamorous images of smoking in movies rated for children under 17.

Nearly 80% of movies rated PG-13 feature some form of tobacco use, while 50% of G and PG rated films depict smoking, said Stanton Glantz, co-author of the study, which examined 775 U.S. movies over the past five years.

"No one is saying there should never be any smoking in the movies," Glantz, a professor of medicine at the University of California, San Francisco, said Tuesday at a press conference at Hollywood High School. "What we're simply asking for is that smoking be treated by Hollywood as seriously as it treats offensive language."

He'd like to see more PG-13 movies that feature smoking — like Matchstick Men,Seabiscuit and the Oscar-winning Chicago— get slapped with an R rating.

Since R-rated films typically earn less money because they are not open to most teenagers, Glantz said he hoped such a policy would discourage filmmakers from depicting unnecessary smoking, such as the nicotine-addicted worm aliens in Men in Black.

The proposal includes an exception for historical figures who actually smoked as part of their public life, Glantz added. "For example, if they wanted to make a movie about Winston Churchill, they could show him with a cigar without triggering an R-rating, but the number of movies where that actually happens is very small."

The study was funded by the charitable foundation The Richard and Rhoda Goldman Fund and the National Cancer Institute.

Glantz singled out The Walt Disney Co. for smoking in the PG-rated Holes and G-rated 102 Dalmatians, Time Warner for its PG Secondhand Lions and What a Girl Wants and Sony Pictures Entertainment for its PG Master of Disguise.

The Motion Picture Association of America, which rates films, did not immediately return calls for comment on the study or the ratings proposal.

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